It's About Time
ran from sept 11/66 to aug 27/67
Starred Jack Mullaney & Frank Aletter as two 1960's astronauts who break the time barrier and end up in prehistoric times.

http://www.tvparty.com/recits.html

Real surprised its not even listed....I watched this when I was 8 yrs old
produced by the immortal Sherwood Schwartz, creator of The Brady Bunch and Gilligan's Island (Gilligan was then in its third year earning solid ratings for CBS).
Joe E. Ross as Gronk - with another comedy legend, Imogene Coca (Your Show of Shows) seen as his nagging wife Shadd.

Discussions for that series can be found in the Spin-offs and One-Year Wonders Forum here. (http://www.sitcomsonline.com/boards/search.php?searchid=1275113)

This show had one the best theme songs ever!!:wave:

I remember this series. It had a great theme song.